Prologue about Ninja: The ninja also known as shinobi, who was a hired soldier of Japan during the feudal ages. The ninjas specialized in unorthodox methods of warfare. The ninja had many functions dealing with, spying, infiltrating, sabotaging and assassinating. They were well-known for their precision, skill and use of ninja weapons. The ninja with it's under cover strategy was the opposite of the bold samurai who were very careful about their above board reputation.
Military historian Hanawa Hokioichi wrote that the ninjas disguised themselves while entering enemy territory to gauge opponent's strength. They would blend in with the opponent to find the lapses and often creep into fort to set them on fire. Arriving secretly they carried out assassinations.
It is guessed that the ninja group originated around 14th century. After many years of obscurity they came into prominence during 17th and 18th centuries. Ninjutsu came to be connected with many practices of the ninja - a mixture of philosophy and religion being applied to the art of war including spying.
The imagination of Japan has always romanticized on the mysterious character of the ninjas. Later this has spread to other parts of the world. Ninja figures dominate folk tales and myths - making it difficult to separate it from history. There are legends about the ninja becoming invisible, walking on water and having full control over the elements. Today it has entered the entertainment zone of modern times.
Ancestry of the Ninja's: The ninjas came from clans. In the pre-modern ancient Iga Province lived the Iga and Koga clans. In this region the villagers were mainly engaged in being trained to be ninjas. It was an ideal place for such activities because the region was remote, Inaccessible and encircled by mountains.
There is a difference between the ninja coming from these regions and the common ones who were engaged as mercenary spies. The Iga and Koga clans produced ninjas who were professionals having got specific training. They were hired by the daimyo.
The daimyos was powerful warlords in medieval times who ruled over the major parts of the country from their huge inherited landed property. In the late 16th century Oda Nobunaga, aggressively conquered nearly a third of the other daimyos and after invading Iga province exterminated the organized ninja clans. The survivors fled and were scattered. In some places they were made most welcome for obvious reasons. Many took shelter in the Kii Mountains.
In 1560 after the Battle of Okehazama, the warlord Oda Nobunaga emerged all powerful and took into his employment a group of ninjas from the Koja clan numbering 80. They stealthily entered a castle of the enemy and set its towers ablaze while killing the castellan or the governor of the castle.